Most have come down in support of Apple, though others, including Bill Gates and Simon Segars, CEO of UK chip company ARM, have leaned more towards the FBI's position.
Here's a roundup of what tech leaders have said so far, starting with some of the most recent views expressed.
Bill Gates
On Monday, the Microsoft cofounder took issue with Apple's characterization that the government wants a "back door" to the iPhone.
“Nobody’s taking about a back door, so that’s not the right question," Gates said. "This is a specific case where the government is asking for access to information. They're not asking for some general thing; they're asking for a particular case."
The next day, Gates said headlines stating that he "backs the FBI" don't reflect his position.
"I was disappointed because that doesn't state my view on this," he told Bloomberg. "I do believe that with the right safeguards, there are cases where the government, on our behalf, like stopping terrorism, which could get worse in the future, that that is valuable. But striking that balance -- clearly the government has taken information historically and used it in ways we didn't expect, going all the way back to say the FBI under J. Edgar Hoover. I'm hoping now we can have the discussion. I do believe there are sets of safeguards where the government shouldn't have to be completely blind."
ARM CEO Simon Segars
Segars, whose company designs the microprocessors in most smartphones, was asked his views at Mobile World Congress in Barcelona.
“It’s a complex situation; there are rights and wrongs,” Segars said.
“We believe users should own their data and control who has access to it, but obviously there are some extreme circumstances where that should change."
Mark Zuckerberg
“We’re sympathetic with Apple,” the Facebook CEO said at Mobile World Congress in Barcelona on Monday. “We believe encryption is a good thing that people will want.”
In a statement earlier, Facebook said the FBI's demands would create "a chilling precedent and obstruct companies’ efforts to secure their products."
Jan Koum, cofounder of WhatsApp
Koum was among the first tech leaders to speak out, taking to his Facebook page the day after Apple said it would oppose the FBI's request.
"I have always admired Tim Cook for his stance on privacy and Apple's efforts to protect user data and couldn't agree more with everything said in their Customer Letter today," Koum wrote. "We must not allow this dangerous precedent to be set. Today our freedom and our liberty is at stake."
Google CEO Sundar Pichai
Pichai soon followed with a series of tweets.
"Important post by @tim_cook. Forcing companies to enable hacking could compromise users’ privacy," Pichai tweeted on Feb. 17.
He continued: "We know that law enforcement and intelligence agencies face significant challenges in protecting the public against crime and terrorism. We build secure products to keep your information safe and we give law enforcement access to data based on valid legal orders. But that’s wholly different than requiring companies to enable hacking of customer devices & data. Could be a troubling precedent. Looking forward to a thoughtful and open discussion on this important issue."
Twitter CEO Jack Dorsey
Dorsey chimed in with a tweet on Feb. 18.
“We stand with @timcook and Apple (and thank him for his leadership)!”
Box CEO Aaron Levie
“Apple’s response to the government is something we completely, wholeheartedly agree with,” the cloud storage CEO told TechCrunch. “The world is going to get more complex, so you can’t create weaknesses in software that then will become vulnerabilities in the future.”
Mark Surman, executive director of the Mozilla Foundation
"Over the last year, we’ve seen government agencies and law enforcement officials across the globe discussing policies that will harm user security through weakening encryption," Surman wrote on Medium last week. "This includes the so called Snoopers Charter in the UK and calls by agencies like the FBI for tech companies to create backdoors into encrypted communications. ... While it’s hard to discuss internet policy in the the context of horrific and tragic events, there is no question [the] FBI’s request [is] an overreach. If granted, it both undermines everyday security for Internet users and would set a precedent for further weakening of encryption.
Outside the tech industry
While the tech industry largely supports Apple's position, the American public does not according to a study by the Pew Research Center. And there are plenty of voices outside of tech who back the FBI, including the White House, Donald Trump, and William Bratton, the New York City police commissioner, who cowrote an op-ed in the New York Times Tuesday.
"Mr. Cook says Apple’s ultimate goal is to provide customers 'safety' from 'attack," the op-ed reads. "But Mr. Cook does not seem to be talking about the kind of attack that took 14 lives in San Bernardino. Presumably, he means attacks from hackers or what he may view as government intrusion -- even when that intrusion is legal."